An airplane is propelled by one or several propulsive assemblies each comprising a turbojet engine housed in a tubular nacelle. Each propulsive assembly is attached to an aircraft by a mast situated under a wing or at the fuselage.
A nacelle generally has a structure comprising an air intake upstream of the engine and a middle section able to surround a fan of the turbojet engine, a downstream section generally housing thrust reverser means and able to surround the combustion chamber of the turbojet engine. The nacelle typically ends with an ejection nozzle, the outlet of which is situated downstream of the turbojet engine.
The air intake comprises, on one hand, an intake lip adapted to allow optimal collection towards the turbojet engine of the air necessary to supply the fan and the internal compressors of the turbojet engine, and on the other hand, a downstream structure, on which the lip is attached, intended to suitably channel the air towards the blades of the fan. The assembly is attached upstream of a case of the fan belonging to the upstream section of the nacelle.
In flight, depending on the temperature and moisture conditions, ice can form on the nacelle in various places including the outer surface of the air intake lip. The presence of ice or frost modifies the aerodynamic properties of the air intake and disturbs the conveyance of the air towards the fan.
One solution for de-frosting or de-icing the nacelle, in particular the outer surface of the air intake lip, consists of preventing ice from forming on the wall by heating the latter parts using an electric heating resistor. The heating resistor is typically mounted on or in the outer wall of an element to be de-iced, for example in the case where the heating resistors are in the form of leaves.
However, such an element is difficult to manufacture due to the geometry of the wall. Indeed, the de-icing device must not interfere with other performance by the element of the nacelle such as absorption of the noises generated by the operation of the turbojet engine. In particular, the heating resistor must not interfere with the holes therein, for example by blocking said holes.
In the case where the electric resistor is in the form of leaves and in the case where the acoustic holes were made first, the placement of said leaves around the acoustic holes is difficult. In the case where the resistive leaves are placed first, the perforation of said leaves to obtain acoustic holes damages the acoustic resistor.
Moreover, the heating resistors of the prior art are generally integrated manually on composite supports. Because of this, making these resistors is lengthy and complex.
Moreover, the manufacturing limits and location of the heating resistors vary depending on the operators.